Herbicide compositions are often characterized according to the identity of the active ingredient, and by the mode by which the active ingredient causes vegetation necrosis. Regardless of the active ingredient, most herbicides cause vegetation necrosis by interfering with one or more vital biological processes essential to the vegetation's survival. Yet, before the active ingredient of a herbicide can interfere with such biological processes, the active ingredient must somehow be absorbed into the vegetation. Unfortunately, this absorption is often hindered by the chemical nature of the active ingredient.
Accordingly, in addition to active ingredients, most herbicide compositions also include other components, commonly termed adjuvants, that enhance the performance and absorption of the active ingredient. One class of adjuvants that is frequently used is surfactants. Surfactants are useful in herbicide compositions because they tend to both enhance the absorbing properties of the active ingredient, as well as facilitate application of the herbicide.
Several existing patents disclose various classes of amine-based surfactant adjuvants. For example, U.S. Pat. No. 5,683,958 discloses surfactant compositions comprising polyoxyalkylene alkylamines. U.S. Pat. No. 5,798,310 discloses adjuvants comprising alkoxylated quaternary ammonium surfactants. U.S. Pat. No. 5,668,085 discloses glyphosate formulations comprising alkoxylated amine surfactants. And, U.S. Pat. No. 5,118,444 discloses amine-oxide surfactants produced by oxidizing tertiary polyalkoxylated amine surfactants.
Several existing patents also disclose various sulfosuccinate or sulfosuccinamate-based surfactants that are useful in a variety of applications. For example, U.S. Pat. No. 5,762,757 discloses methods of inhibiting the deposition of organic contaminants from pulp in papermaking and pulp systems through the use of a combination of dioctylsulfosuccinate and didecyl sulfosuccinate anionic surfactants. U.S. Pat. No. 5,480,586 discloses a liquid detergent composition comprising a sulfosuccinamate-containing surfactant blend. U.S. Pat. No. 5,236,710 discloses cosmetic compositions containing an emulsifying copolymer and anionic sulfosuccinate. And, U.S. Pat. No. 5,015,414 discloses a low-irritant detergent composition containing an alkyl saccharide and sulfosuccinate surfactants.
However, the literature appears to lack any reference to the combined use of an amine-based surfactant and a sulfosuccinate or sulfosuccinamate-based surfactant as a herbicide adjuvant. It was discovered that the bioefficacy of amine-based surfactant adjuvants may be enhanced with the addition of a sulfosuccinate or sulfosuccinamate-based surfactant. Accordingly, the present invention is directed toward surfactant adjuvants that comprise an amine-based surfactant and a sulfosuccinate or sulfosuccinamate-based surfactant, herbicide compositions comprising such surfactant adjuvants, and a method of controlling unwanted vegetation using such herbicide compositions.